2 // delegate.cs: Delegate Handler
5 // Ravi Pratap (ravi@ximian.com)
6 // Miguel de Icaza (miguel@ximian.com)
7 // Marek Safar (marek.safar@gmail.com)
9 // Dual licensed under the terms of the MIT X11 or GNU GPL
11 // Copyright 2001 Ximian, Inc (http://www.ximian.com)
12 // Copyright 2003-2009 Novell, Inc (http://www.novell.com)
18 using IKVM.Reflection;
19 using IKVM.Reflection.Emit;
21 using System.Reflection;
22 using System.Reflection.Emit;
25 namespace Mono.CSharp {
28 // Delegate container implementation
30 public class Delegate : TypeContainer, IParametersMember
32 FullNamedExpression ReturnType;
33 readonly ParametersCompiled parameters;
35 Constructor Constructor;
37 Method BeginInvokeBuilder;
38 Method EndInvokeBuilder;
40 static readonly string[] attribute_targets = new string [] { "type", "return" };
42 public static readonly string InvokeMethodName = "Invoke";
44 Expression instance_expr;
45 ReturnParameter return_attributes;
47 const Modifiers MethodModifiers = Modifiers.PUBLIC | Modifiers.VIRTUAL;
49 const Modifiers AllowedModifiers =
57 public Delegate (NamespaceContainer ns, DeclSpace parent, FullNamedExpression type,
58 Modifiers mod_flags, MemberName name, ParametersCompiled param_list,
60 : base (ns, parent, name, attrs, MemberKind.Delegate)
63 this.ReturnType = type;
64 ModFlags = ModifiersExtensions.Check (AllowedModifiers, mod_flags,
65 IsTopLevel ? Modifiers.INTERNAL :
66 Modifiers.PRIVATE, name.Location, Report);
67 parameters = param_list;
68 spec = new TypeSpec (Kind, null, this, null, ModFlags | Modifiers.SEALED);
72 public TypeSpec MemberType {
74 return ReturnType.Type;
78 public AParametersCollection Parameters {
85 public override void Accept (StructuralVisitor visitor)
90 public override void ApplyAttributeBuilder (Attribute a, MethodSpec ctor, byte[] cdata, PredefinedAttributes pa)
92 if (a.Target == AttributeTargets.ReturnValue) {
93 if (return_attributes == null)
94 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
96 return_attributes.ApplyAttributeBuilder (a, ctor, cdata, pa);
100 base.ApplyAttributeBuilder (a, ctor, cdata, pa);
103 public override AttributeTargets AttributeTargets {
105 return AttributeTargets.Delegate;
109 protected override bool DoDefineMembers ()
111 var builtin_types = Compiler.BuiltinTypes;
113 var ctor_parameters = ParametersCompiled.CreateFullyResolved (
115 new Parameter (new TypeExpression (builtin_types.Object, Location), "object", Parameter.Modifier.NONE, null, Location),
116 new Parameter (new TypeExpression (builtin_types.IntPtr, Location), "method", Parameter.Modifier.NONE, null, Location)
119 builtin_types.Object,
124 Constructor = new Constructor (this, Constructor.ConstructorName,
125 Modifiers.PUBLIC, null, ctor_parameters, null, Location);
126 Constructor.Define ();
129 // Here the various methods like Invoke, BeginInvoke etc are defined
131 // First, call the `out of band' special method for
132 // defining recursively any types we need:
136 if (!p.Resolve (this))
143 // Check accessibility
144 foreach (var partype in p.Types) {
145 if (!IsAccessibleAs (partype)) {
146 Report.SymbolRelatedToPreviousError (partype);
147 Report.Error (59, Location,
148 "Inconsistent accessibility: parameter type `{0}' is less accessible than delegate `{1}'",
149 TypeManager.CSharpName (partype), GetSignatureForError ());
153 var ret_type = ReturnType.ResolveAsType (this);
154 if (ret_type == null)
158 // We don't have to check any others because they are all
159 // guaranteed to be accessible - they are standard types.
161 if (!IsAccessibleAs (ret_type)) {
162 Report.SymbolRelatedToPreviousError (ret_type);
163 Report.Error (58, Location,
164 "Inconsistent accessibility: return type `" +
165 TypeManager.CSharpName (ret_type) + "' is less " +
166 "accessible than delegate `" + GetSignatureForError () + "'");
170 CheckProtectedModifier ();
172 if (Compiler.Settings.StdLib && ret_type.IsSpecialRuntimeType) {
173 Method.Error1599 (Location, ret_type, Report);
177 TypeManager.CheckTypeVariance (ret_type, Variance.Covariant, this);
179 InvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName (InvokeMethodName), p, null);
180 InvokeBuilder.Define ();
183 // Don't emit async method for compiler generated delegates (e.g. dynamic site containers)
185 if (!IsCompilerGenerated) {
186 DefineAsyncMethods (Parameters.CallingConvention);
192 void DefineAsyncMethods (CallingConventions cc)
194 var iasync_result = Module.PredefinedTypes.IAsyncResult;
195 var async_callback = Module.PredefinedTypes.AsyncCallback;
198 // It's ok when async types don't exist, the delegate will have Invoke method only
200 if (!iasync_result.Define () || !async_callback.Define ())
206 ParametersCompiled async_parameters;
207 if (Parameters.Count == 0) {
208 async_parameters = ParametersCompiled.EmptyReadOnlyParameters;
210 var compiled = new Parameter[Parameters.Count];
211 for (int i = 0; i < compiled.Length; ++i) {
212 var p = parameters[i];
213 compiled[i] = new Parameter (new TypeExpression (parameters.Types[i], Location),
215 p.ModFlags & (Parameter.Modifier.REF | Parameter.Modifier.OUT),
216 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
219 async_parameters = new ParametersCompiled (compiled);
222 async_parameters = ParametersCompiled.MergeGenerated (Compiler, async_parameters, false,
224 new Parameter (new TypeExpression (async_callback.TypeSpec, Location), "callback", Parameter.Modifier.NONE, null, Location),
225 new Parameter (new TypeExpression (Compiler.BuiltinTypes.Object, Location), "object", Parameter.Modifier.NONE, null, Location)
228 async_callback.TypeSpec,
229 Compiler.BuiltinTypes.Object
233 BeginInvokeBuilder = new Method (this, null,
234 new TypeExpression (iasync_result.TypeSpec, Location), MethodModifiers,
235 new MemberName ("BeginInvoke"), async_parameters, null);
236 BeginInvokeBuilder.Define ();
239 // EndInvoke is a bit more interesting, all the parameters labeled as
240 // out or ref have to be duplicated here.
244 // Define parameters, and count out/ref parameters
246 ParametersCompiled end_parameters;
249 foreach (Parameter p in Parameters.FixedParameters) {
250 if ((p.ModFlags & Parameter.Modifier.ISBYREF) != 0)
254 if (out_params > 0) {
255 Parameter[] end_params = new Parameter[out_params];
258 for (int i = 0; i < Parameters.FixedParameters.Length; ++i) {
259 Parameter p = parameters [i];
260 if ((p.ModFlags & Parameter.Modifier.ISBYREF) == 0)
263 end_params [param++] = new Parameter (new TypeExpression (p.Type, Location),
265 p.ModFlags & (Parameter.Modifier.REF | Parameter.Modifier.OUT),
266 p.OptAttributes == null ? null : p.OptAttributes.Clone (), Location);
269 end_parameters = new ParametersCompiled (end_params);
271 end_parameters = ParametersCompiled.EmptyReadOnlyParameters;
274 end_parameters = ParametersCompiled.MergeGenerated (Compiler, end_parameters, false,
276 new TypeExpression (iasync_result.TypeSpec, Location),
277 "result", Parameter.Modifier.NONE, null, Location),
278 iasync_result.TypeSpec);
281 // Create method, define parameters, register parameters with type system
283 EndInvokeBuilder = new Method (this, null, ReturnType, MethodModifiers, new MemberName ("EndInvoke"), end_parameters, null);
284 EndInvokeBuilder.Define ();
287 public override void DefineConstants ()
289 if (!Parameters.IsEmpty) {
290 parameters.ResolveDefaultValues (this);
294 public override void EmitType ()
296 if (ReturnType.Type != null) {
297 if (ReturnType.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
298 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
299 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder);
300 } else if (ReturnType.Type.HasDynamicElement) {
301 return_attributes = new ReturnParameter (this, InvokeBuilder.MethodBuilder, Location);
302 Module.PredefinedAttributes.Dynamic.EmitAttribute (return_attributes.Builder, ReturnType.Type, Location);
305 ConstraintChecker.Check (this, ReturnType.Type, ReturnType.Location);
308 Constructor.ParameterInfo.ApplyAttributes (this, Constructor.ConstructorBuilder);
309 Constructor.ConstructorBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
311 parameters.CheckConstraints (this);
312 parameters.ApplyAttributes (this, InvokeBuilder.MethodBuilder);
313 InvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
315 if (BeginInvokeBuilder != null) {
316 BeginInvokeBuilder.ParameterInfo.ApplyAttributes (this, BeginInvokeBuilder.MethodBuilder);
317 EndInvokeBuilder.ParameterInfo.ApplyAttributes (this, EndInvokeBuilder.MethodBuilder);
319 BeginInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
320 EndInvokeBuilder.MethodBuilder.SetImplementationFlags (MethodImplAttributes.Runtime);
323 if (OptAttributes != null) {
324 OptAttributes.Emit ();
330 protected override TypeSpec[] ResolveBaseTypes (out FullNamedExpression base_class)
332 base_type = Compiler.BuiltinTypes.MulticastDelegate;
337 protected override TypeAttributes TypeAttr {
339 return ModifiersExtensions.TypeAttr (ModFlags, IsTopLevel) |
340 TypeAttributes.Class | TypeAttributes.Sealed |
345 public override string[] ValidAttributeTargets {
347 return attribute_targets;
352 protected override bool VerifyClsCompliance ()
354 if (!base.VerifyClsCompliance ()) {
358 parameters.VerifyClsCompliance (this);
360 if (!InvokeBuilder.MemberType.IsCLSCompliant ()) {
361 Report.Warning (3002, 1, Location, "Return type of `{0}' is not CLS-compliant",
362 GetSignatureForError ());
368 public static MethodSpec GetConstructor (TypeSpec delType)
370 var ctor = MemberCache.FindMember (delType, MemberFilter.Constructor (null), BindingRestriction.DeclaredOnly);
371 return (MethodSpec) ctor;
375 // Returns the "Invoke" from a delegate type
377 public static MethodSpec GetInvokeMethod (TypeSpec delType)
379 var invoke = MemberCache.FindMember (delType,
380 MemberFilter.Method (InvokeMethodName, 0, null, null),
381 BindingRestriction.DeclaredOnly);
383 return (MethodSpec) invoke;
386 public static AParametersCollection GetParameters (TypeSpec delType)
388 var invoke_mb = GetInvokeMethod (delType);
389 return invoke_mb.Parameters;
393 // 15.2 Delegate compatibility
395 public static bool IsTypeCovariant (ResolveContext rc, TypeSpec a, TypeSpec b)
398 // For each value parameter (a parameter with no ref or out modifier), an
399 // identity conversion or implicit reference conversion exists from the
400 // parameter type in D to the corresponding parameter type in M
405 if (rc.Module.Compiler.Settings.Version == LanguageVersion.ISO_1)
408 if (a.IsGenericParameter && b.IsGenericParameter)
411 return Convert.ImplicitReferenceConversionExists (a, b);
414 public static string FullDelegateDesc (MethodSpec invoke_method)
416 return TypeManager.GetFullNameSignature (invoke_method).Replace (".Invoke", "");
419 public Expression InstanceExpression {
421 return instance_expr;
424 instance_expr = value;
430 // Base class for `NewDelegate' and `ImplicitDelegateCreation'
432 public abstract class DelegateCreation : Expression, OverloadResolver.IErrorHandler
434 protected MethodSpec constructor_method;
435 protected MethodGroupExpr method_group;
437 public override bool ContainsEmitWithAwait ()
442 public static Arguments CreateDelegateMethodArguments (AParametersCollection pd, TypeSpec[] types, Location loc)
444 Arguments delegate_arguments = new Arguments (pd.Count);
445 for (int i = 0; i < pd.Count; ++i) {
446 Argument.AType atype_modifier;
447 switch (pd.FixedParameters [i].ModFlags) {
448 case Parameter.Modifier.REF:
449 atype_modifier = Argument.AType.Ref;
451 case Parameter.Modifier.OUT:
452 atype_modifier = Argument.AType.Out;
459 delegate_arguments.Add (new Argument (new TypeExpression (types [i], loc), atype_modifier));
462 return delegate_arguments;
465 public override Expression CreateExpressionTree (ResolveContext ec)
467 MemberAccess ma = new MemberAccess (new MemberAccess (new QualifiedAliasMember ("global", "System", loc), "Delegate", loc), "CreateDelegate", loc);
469 Arguments args = new Arguments (3);
470 args.Add (new Argument (new TypeOf (type, loc)));
472 if (method_group.InstanceExpression == null)
473 args.Add (new Argument (new NullLiteral (loc)));
475 args.Add (new Argument (method_group.InstanceExpression));
477 args.Add (new Argument (method_group.CreateExpressionTree (ec)));
478 Expression e = new Invocation (ma, args).Resolve (ec);
482 e = Convert.ExplicitConversion (ec, e, type, loc);
486 return e.CreateExpressionTree (ec);
489 protected override Expression DoResolve (ResolveContext ec)
491 constructor_method = Delegate.GetConstructor (type);
493 var invoke_method = Delegate.GetInvokeMethod (type);
495 Arguments arguments = CreateDelegateMethodArguments (invoke_method.Parameters, invoke_method.Parameters.Types, loc);
496 method_group = method_group.OverloadResolve (ec, ref arguments, this, OverloadResolver.Restrictions.CovariantDelegate);
497 if (method_group == null)
500 var delegate_method = method_group.BestCandidate;
502 if (delegate_method.DeclaringType.IsNullableType) {
503 ec.Report.Error (1728, loc, "Cannot create delegate from method `{0}' because it is a member of System.Nullable<T> type",
504 delegate_method.GetSignatureForError ());
508 Invocation.IsSpecialMethodInvocation (ec, delegate_method, loc);
510 ExtensionMethodGroupExpr emg = method_group as ExtensionMethodGroupExpr;
512 method_group.InstanceExpression = emg.ExtensionExpression;
513 TypeSpec e_type = emg.ExtensionExpression.Type;
514 if (TypeSpec.IsValueType (e_type)) {
515 ec.Report.Error (1113, loc, "Extension method `{0}' of value type `{1}' cannot be used to create delegates",
516 delegate_method.GetSignatureForError (), TypeManager.CSharpName (e_type));
520 TypeSpec rt = delegate_method.ReturnType;
521 if (!Delegate.IsTypeCovariant (ec, rt, invoke_method.ReturnType)) {
522 Expression ret_expr = new TypeExpression (rt, loc);
523 Error_ConversionFailed (ec, delegate_method, ret_expr);
526 if (delegate_method.IsConditionallyExcluded (ec.Module.Compiler, loc)) {
527 ec.Report.SymbolRelatedToPreviousError (delegate_method);
528 MethodOrOperator m = delegate_method.MemberDefinition as MethodOrOperator;
529 if (m != null && m.IsPartialDefinition) {
530 ec.Report.Error (762, loc, "Cannot create delegate from partial method declaration `{0}'",
531 delegate_method.GetSignatureForError ());
533 ec.Report.Error (1618, loc, "Cannot create delegate with `{0}' because it has a Conditional attribute",
534 TypeManager.CSharpSignature (delegate_method));
538 var expr = method_group.InstanceExpression;
539 if (expr != null && (expr.Type.IsGenericParameter || !TypeSpec.IsReferenceType (expr.Type)))
540 method_group.InstanceExpression = new BoxedCast (expr, ec.BuiltinTypes.Object);
542 eclass = ExprClass.Value;
546 public override void Emit (EmitContext ec)
548 if (method_group.InstanceExpression == null)
551 method_group.InstanceExpression.Emit (ec);
553 var delegate_method = method_group.BestCandidate;
555 // Any delegate must be sealed
556 if (!delegate_method.DeclaringType.IsDelegate && delegate_method.IsVirtual && !method_group.IsBase) {
557 ec.Emit (OpCodes.Dup);
558 ec.Emit (OpCodes.Ldvirtftn, delegate_method);
560 ec.Emit (OpCodes.Ldftn, delegate_method);
563 ec.Emit (OpCodes.Newobj, constructor_method);
566 void Error_ConversionFailed (ResolveContext ec, MethodSpec method, Expression return_type)
568 var invoke_method = Delegate.GetInvokeMethod (type);
569 string member_name = method_group.InstanceExpression != null ?
570 Delegate.FullDelegateDesc (method) :
571 TypeManager.GetFullNameSignature (method);
573 ec.Report.SymbolRelatedToPreviousError (type);
574 ec.Report.SymbolRelatedToPreviousError (method);
575 if (ec.Module.Compiler.Settings.Version == LanguageVersion.ISO_1) {
576 ec.Report.Error (410, loc, "A method or delegate `{0} {1}' parameters and return type must be same as delegate `{2} {3}' parameters and return type",
577 TypeManager.CSharpName (method.ReturnType), member_name,
578 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
582 if (return_type == null) {
583 ec.Report.Error (123, loc, "A method or delegate `{0}' parameters do not match delegate `{1}' parameters",
584 member_name, Delegate.FullDelegateDesc (invoke_method));
588 ec.Report.Error (407, loc, "A method or delegate `{0} {1}' return type does not match delegate `{2} {3}' return type",
589 return_type.GetSignatureForError (), member_name,
590 TypeManager.CSharpName (invoke_method.ReturnType), Delegate.FullDelegateDesc (invoke_method));
593 public static bool ImplicitStandardConversionExists (ResolveContext ec, MethodGroupExpr mg, TypeSpec target_type)
595 // if (target_type == TypeManager.delegate_type || target_type == TypeManager.multicast_delegate_type)
598 var invoke = Delegate.GetInvokeMethod (target_type);
600 Arguments arguments = CreateDelegateMethodArguments (invoke.Parameters, invoke.Parameters.Types, mg.Location);
601 return mg.OverloadResolve (ec, ref arguments, null, OverloadResolver.Restrictions.CovariantDelegate | OverloadResolver.Restrictions.ProbingOnly) != null;
604 #region IErrorHandler Members
606 bool OverloadResolver.IErrorHandler.AmbiguousCandidates (ResolveContext ec, MemberSpec best, MemberSpec ambiguous)
611 bool OverloadResolver.IErrorHandler.ArgumentMismatch (ResolveContext rc, MemberSpec best, Argument arg, int index)
613 Error_ConversionFailed (rc, best as MethodSpec, null);
617 bool OverloadResolver.IErrorHandler.NoArgumentMatch (ResolveContext rc, MemberSpec best)
619 Error_ConversionFailed (rc, best as MethodSpec, null);
623 bool OverloadResolver.IErrorHandler.TypeInferenceFailed (ResolveContext rc, MemberSpec best)
632 // Created from the conversion code
634 public class ImplicitDelegateCreation : DelegateCreation
636 ImplicitDelegateCreation (TypeSpec t, MethodGroupExpr mg, Location l)
639 this.method_group = mg;
643 static public Expression Create (ResolveContext ec, MethodGroupExpr mge,
644 TypeSpec target_type, Location loc)
646 ImplicitDelegateCreation d = new ImplicitDelegateCreation (target_type, mge, loc);
647 return d.DoResolve (ec);
652 // A delegate-creation-expression, invoked from the `New' class
654 public class NewDelegate : DelegateCreation
656 public Arguments Arguments;
659 // This constructor is invoked from the `New' expression
661 public NewDelegate (TypeSpec type, Arguments Arguments, Location loc)
664 this.Arguments = Arguments;
668 protected override Expression DoResolve (ResolveContext ec)
670 if (Arguments == null || Arguments.Count != 1) {
671 ec.Report.Error (149, loc, "Method name expected");
675 Argument a = Arguments [0];
676 if (!a.ResolveMethodGroup (ec))
679 Expression e = a.Expr;
681 AnonymousMethodExpression ame = e as AnonymousMethodExpression;
682 if (ame != null && ec.Module.Compiler.Settings.Version != LanguageVersion.ISO_1) {
683 e = ame.Compatible (ec, type);
687 return e.Resolve (ec);
690 method_group = e as MethodGroupExpr;
691 if (method_group == null) {
692 if (e.Type.BuiltinType == BuiltinTypeSpec.Type.Dynamic) {
693 e = Convert.ImplicitConversionRequired (ec, e, type, loc);
694 } else if (!e.Type.IsDelegate) {
695 e.Error_UnexpectedKind (ec, ResolveFlags.MethodGroup | ResolveFlags.Type, loc);
700 // An argument is not a method but another delegate
702 method_group = new MethodGroupExpr (Delegate.GetInvokeMethod (e.Type), e.Type, loc);
703 method_group.InstanceExpression = e;
706 return base.DoResolve (ec);
711 // Invocation converted to delegate Invoke call
713 class DelegateInvocation : ExpressionStatement
715 readonly Expression InstanceExpr;
719 public DelegateInvocation (Expression instance_expr, Arguments args, Location loc)
721 this.InstanceExpr = instance_expr;
722 this.arguments = args;
726 public override bool ContainsEmitWithAwait ()
728 return InstanceExpr.ContainsEmitWithAwait () || (arguments != null && arguments.ContainsEmitWithAwait ());
731 public override Expression CreateExpressionTree (ResolveContext ec)
733 Arguments args = Arguments.CreateForExpressionTree (ec, this.arguments,
734 InstanceExpr.CreateExpressionTree (ec));
736 return CreateExpressionFactoryCall (ec, "Invoke", args);
739 protected override Expression DoResolve (ResolveContext ec)
741 TypeSpec del_type = InstanceExpr.Type;
742 if (del_type == null)
746 // Do only core overload resolution the rest of the checks has been
747 // done on primary expression
749 method = Delegate.GetInvokeMethod (del_type);
750 var res = new OverloadResolver (new MemberSpec[] { method }, OverloadResolver.Restrictions.DelegateInvoke, loc);
751 var valid = res.ResolveMember<MethodSpec> (ec, ref arguments);
752 if (valid == null && !res.BestCandidateIsDynamic)
755 type = method.ReturnType;
756 eclass = ExprClass.Value;
760 public override void Emit (EmitContext ec)
763 // Invocation on delegates call the virtual Invoke member
764 // so we are always `instance' calls
766 var call = new CallEmitter ();
767 call.InstanceExpression = InstanceExpr;
768 call.EmitPredefined (ec, method, arguments);
771 public override void EmitStatement (EmitContext ec)
775 // Pop the return value if there is one
777 if (type.Kind != MemberKind.Void)
778 ec.Emit (OpCodes.Pop);
781 public override System.Linq.Expressions.Expression MakeExpression (BuilderContext ctx)
783 return Invocation.MakeExpression (ctx, InstanceExpr, method, arguments);